Simulating a potentometer in Pspice

[MAKeller]

Gentlemen;


I'm trying to find out how to simulate a
potentometer and use it in a bridge circuit.

I think the best way to do this is with a
voltage controlled resistor.

Maybe I should use a couple of VSRC's in a subcircuit.

Have tried several ideas but the circuit doesn't output
my expected values. It never swings negative.

MAKeller

 

[papyaki]

Hi,

An example of potentiometer simulation is given in the link below by using a ".param" statement :

h**p://www.edn.com/archives/1997/032797/07di_01.htm

Replace * by t

 

[MAKeller]

Have tried the .PARM.
It sweeps the resistor as it should.
Unfortunely the output is positive only.
It should sweep output both negative and positive.

The wheatstone bridge is a differential circuit.
A potentometer is often put in a bridge to produce
a differential output.

I am trying to simulate such a circuit.

Thanks.

MAKeller

 

[VVV]

Either of the two methods will work.

Please don't be offended by this question, but are you measuring the bridge's output voltage DIFFERENTIALLY ?

 

[MAKeller]

No offense taken, I have over 20 years
experience and still learn new things everyday.

I am measuring the output with .Probe (V+ - V-).

Do you know of any other way?

Any opinions or experiences are welcomed.

I am using Pspice 8.0 , 9.2.

MAKeller

 

[drasta]

I think that with .PARAM and .STEP PARAM you can sweep wide range and see what happends, you dont need some special model.

 

[MAKeller]

Guys,

I'm not having a problem sweeping the
circuit, I just get the wrong output.

Does anyone have experience simulating
a wheatstone bridge circuit?

Thanks.

MAKeller